Electrical coil and method of winding same.



E. F. PARKS. ELECTRICAL COIL AND METHOD OF WINDING SAME.

APPLICATION FILED MAR. I5, 19H. I 1 ,27 8,99 3 Patented Sept. 17 1918.

2 SHEETS'SHEET I.

q ATTO NE S E. F. PARKS. ELECTRICAL colL AND METHOD OF wmnme SAME.

APPLICATION FILED MAR. 15, 19117 1,278,993. PatentedSept17,1918.

2 sflEyETS-SHEET 2- UNITED STATES PATENT OFFICE.

EDWARD F. PARKS, 0F PROVIDENCE, RHODE ISLAND, -ASSIGNOIR. TO UNIVERSAL.

SSACHUSETTS, A. CORPORATION OF MASSA- WINDING COMPANY, OF BOSTON, MA GHUSETTS.

ELECTRICAL COIL AND METHOD OF WINDING SAME.

conductor are separated by sheets of paper or strips of similar insulating-material inserted between the layers.

The object of my improvement is to provide means for holding the turns of wire in place as they are coiled on the surface of the paper strip to prevent them from sliding laterally or slipping out'of position, whereby to maintain all of the several turns in each layer in closely contiguous relation. To this end my invention consists particularly in scoring or creasing the sheets'or strips of paperor other material to provide raised shoulders or fin-like ridges extending longitudinally of their marginal edges and adapted to abut the end turns of wire to prevent displacement thereof. The scoring or creasing of the paper may be accomplished previous to, Or during, the operation of feeding it into the coil, the latter being the'preferred method as providing for more economical production of the coil.

the improvement-are fully describe'd in the following specification, illustrated by the accompanying drawings, in which like refer- Specification of Letters Patent. Patented Spt, 1'7, 1918, Application filed March 15, 1917. Serial Nb. 155,114. I

' ridges extending longitudinally of its margi- The manner and means for. carrying out.

ence characters designate like parts. In the drawings Figure 1 is-a sectional view of my im-.

.proved coil taken in a plane intersecting its axis and showing the manner-of creasing the paper strips which are inserted between the 3 layers or wire turns;

Fig. 2, a perspective view of a portion of I the creased insulating strip or sheet;

Fig. 3, a similar view showing the paper strip provided with rows of protuberances along its sides; s

Fi 4, a perspective view of 'the strip showing it creased to provide a plurality of nal edges; I

Fig. 5, a view of the essential elements of the coil-windin mechanism shown in end elevation and il ustrating the method of inserti'ng thepaper or other sheet-material into the coil;

Fig. 6, a front elevation of the same showlng the paper-creasing or scorin rolls; and

Fig. 7, an enlarged, sectional etail of the creasingrolls.

It is now the general practice in producing electrical coils for certain purposes to wind them from enamel-covered wire and to provide insulation between the layers by inserting strips of paper or like sheet-material therebetween. In some cases bare wire is employed and the individual turns or convolutions in each layer are separated and insulated, one from-another, by strands of silk or other textile material. In most cases, however, the wire is first insulated by coating it with enamel which is baked on to provide a hard, glazed surface and this coating renders it extremely smooth and slippery,

making it diflicult to retain it in place during its winding. This tendency of slippage or displacement of the turns of the wire becomes more pronounced as the winding increases in diameter due to the constructive pressure of the outer layers on the inner ones.

Various expedientshave been attempted for. restraining the turns of the windings from slipping or sliding out of place along the coil, such as inserting binding-strips to tie the turns together; cementing each layer of coils in place beforeproceeding with the next; and in other instances by employing abutments or flanges atthe ends of thedayers.

Most of these methods require several manual operations or steps'which impede the windin process and therefore limit the rate of pro uction, so that they are objectionable from an economical standpoint. In my present improvement I have provided a method of-holding the turns of the coil in place which may be appliedas the coil is being wound. without arresting or disturbing the winding operation and without adding to x the cost of production.

Fig, 1 illustrates my improved coil C composed of turnsof wire w wound on a tube or core T with sheets of insulating-material S portions or ridges 8 are arranged to lie alongside the end turns of wire w in the layers L, which are laid on over the paper,

to serve as abutments to hold the coils from spreading or sliding out of place. Fig. 4 shows the sheet S creased to form several ridges 8', 8 at each side and the wire to will lie' between these raised portions of the paper to event the end turns from slipping.

deslred the paper might be creased across. its whole width, but usually this is not required, the single outer creases shown in Fig. 2 being generally suflicient to restrain the coils from movement.

As shown in Fig. 1 the first or inner layers L of wire turns is laid on the bare core or tube T, but if referred a wrapping of the creased sheet S may be applied thereto before'winding on the wire. After the first layer L has been completed with therequired number of turns 10, the sheet S is fed into position to cause it to wrap about the coil, and meanwhile the wire is caused to wind back thereover to hold it in place. As soon as the windings reach the opposite end-of the coil to completethis layer another sheet S is wrapped therearound and 'the wire is traversed back again over this sheet toward the opposite end of the coil. The windingcontinues in this way without interruption with the suc'cessive layers L building up one on another with the sheets S interposed therebetween. As before indicated the distance between the creases or ridges s on the sheets S is proportioned to the length of layer being Wound so that each end coil of each layer will lie in contact with its appropriate crease or abutment. Through this arrangementthe creases 8 at the sides of the strip form annular, raised ledges 0r shoulders which abut the sides ofthe end turns of the wire whereby to hold them from slippage or displacement.

As before stated, the strips or sheets S may be creased in any preferred manner preparatory to inserting them into the coil and the winding of the latter may be accom-- plished either by hand or through the em ployment of the usual rotating arbor and wire-guiding devices. In order to increase the rate of production, however, I prefer to wind the coils with automatically-operating means which not only lays the wire in place,

but also acts to insert the paper strips and to crease them along their margins as they are fed into thecoil. The machine for performing these several functions forms the subject-matter of a separate patent application to be filed later, but in order that the complete method of producing the coil may be now understood I have illustrated the essential elements of the mechanism in the present drawings.

Referring to Fig. 5, B'designatesthe rotating winding-spindle or mandrel which supports the tube T on which the coil is wound, and G is the guiding-pulley over which the Wire leads to direct it to the spindle while traversing it therealong. The pulley or wire guide G is here shown as being carried at the end of an arm E hinged to a rod F, which latter is adapted to be reciprocated parallel with the winding-spindle B through any suitable arrangement of means as usually employed. A pressureroller H carried at the end of a hinged arm 72. is adapted to bear against the turns of wire as they are laid in place on the coil and as the winding increases in diameter the roller H and guide-pulley G swing outwardly from the'axis of the spindle B.

Below the spindle B are two sets of sheetfeeding rolls R, R .which are formed to crease the paper or other strip S as it passes therebetween. ReferringI particularly to Fig. 6, one pair of rolls is mounted on a rotatable shaft m which is driven positively during the strip-feeding cycles by suitable means not here shown. Another pair of rolls R, R is mounted on a\shaft 7c journaled in a frame K which is ivotally supported on a rod '0. The frame i2 is controlled by a spring is, or its equivalent, to cause therolls R, R" to bear against the pkaper or strip S as it feeds over the rolls R,

as shown in Fig. 5; The two rolls R, R are scored with relatively shallow, circumferential grooves r, 1", see enlarged view,

Fig. 7, and the rolls R, R are formed on k to adapt them to be adjusted longitudi-.

nally thereof, and are secured in position by the set-screws o, v or through any other suitable means. The rolls R, R and R, R are adjusted in relation in accordance with the width of the paper or other strip being employed, and in conformity withthe length of coil to be wound. -As shown in Fig. 7, the fin r on each roll R is adapted to run in the-groove r in the roll R with a slight clearance therebetween. Therefore, as the strip S is fed between the rolls, the fins 1" will press the paper into the grooves 7' to crimp or crease it to form the. longitudinal marginal ridges s, s as shown in Fig. 2.

The complete method of operation for winding the coil is as follows: The end of the wire w is first fastened to the tube T and the spindle B is started to rotate while the guide G is givena relatively slow traverse-motion therealong. If a strip of paper is to be first laid on the tube, as is sometimes found expedient to provide an initial, wireretaining means, its end is fed between the rolls R, Rand R, R and its leading edge brought up in under the first turn of the wire on the tube as shown in Fig. 5. As the spindle B rotates it will wrap the paper or other strip S about the tube T and meanwhile the wire w will start to wind there'- over to hold it in place. After the paper has been Wrapped around the tube T one or more times,.in accordance with the thickness desired, the strip 'is severed at the required point and the wire continues to be wound onto the tube until the prescribed number of turns are in place. As soon as the layer of wire is completed in this manner the movement of the traverse-guide G is reversed and the wire starts to wind back again in theopposite direction. Meanwhile, another length of paper is inserted under the first turn of the wire and this is applied around the outside of the first layer of the coil as illustrated in Fig. 1.' This cycle of v operations continues to wind the wire into the coil, layer on layer, with the paper stri s interposed therebetween. Preferably, t e feedin of the'paper is accomplished automatica ly at predetermined intervals of the winding as each new layer is commenced, and the strip is also cut off through the operation of automatically-controlled means which are not herein shown or described as an explanation of their method of operation v is not necessary'to an understanding of the present invention. Through the employment of these automatic means, however, the winding of the coil may be carried on continuously without arresting the operation to insert the strips of insulation and hence the rate of production is greatly increased.

As the paper feeds into the coil it is formed with the creases or ridges which assume a position contiguous to the end turns of the wire and thus act as supporting or retaining abutments to hold the windings in place. After the winding operation is finished the coil is usually impregnated .with shellac, bakelite, or some other cementitious compound, forced thereinto under paper also stifi'e'ns its texture and reinforces its creased portions so that these will have an added strength to hold the windings in place; Through this means the wire turns are held securely in position inv contiguous relation as required to maintain the physical structure and electrical efiiciency of the coil. My improved method of producingthe coil, therefore, pot only makes for economyv in its manufacture, by eliminating manual operations, but also saves theuse of bodiment shown, what I claim is 1. An improved coil for electrical pur poses composed of a succession of layers of turns of conducting-material, with relatively thin sheets of insulatingmaterial such aspaper interposed therebetween, each sheet belng creased along its marginal edges to form fin-like ridges projecting from its surface into position to abut theend turns of the wire in each layer to restrain them from sliding or slipping out of place.

2. Animproved coil for electrical purposes comprising superiiriposed layers of windings of wire, and-intervening sheets of relatively thin insulating-material such as paper inserted between the wire layers, said sheets being provided with creased portions pressed up from their surfaces and disposed in position to abut the sides of the wire windings to hold them in place and prevent .100

them from slipping longitudinally of the coil.

3. An improved coil for electrical purposes comprising a series of superimposed layers of wire windings with relatively thin sheets of paper interposed therebetween to insulate the layers one from another, said paper being scored or creased to raise its surface in annular fin-like ridges'extending circumferentially of the coil inposition to lie alongside the turns of the wire in each layer whereby to prevent lateral displacement thereof.

4. An. improved method of producing electrical coils consisting in winding a conductor in successive layers of convolutions or turns and inserting sheets of insulatingmaterial between the layers, said sheetsbeing creased longitudinally of thelr marginal edges to form .fin-like ridges which assume a position contiguous to the sides of the .wire turns to hold them in place and prevent them from slipping on the surface of the sheets,

5. An improved method of producing electrical coils consisting in winding wire in successive layers disposed about a central core and wrapping a strip of paper around each layer after its completion, said strip being previouslycreased to raise fin-hl'e ridges on its outer surface whereby to form abutments adapted to lie alongside -the turns of wire-laid over the paper to restain the windings from lateral displacement or slippage.

6. An improved method of producing electrical-coils consisting in winding wire on a central core in a succession of superimposed layers, and periodically feeding sheets of insulating-material into the coil to cover each layer at its completion, While concurrently creasing the sheets longitudinally of their marginal edges during the feeding operation to form annular fin-like ridges pro-" jecting from the surface thereof when the sheets are wra ped' around the layers to abut the sides 0 the wire turns wound thereover.

7 An improved method of producingelectrical-coils consisting in winding wire on a continuously rotating mandrelwhiletraversing it back and forth longitudinally thereof to dispose the turns in concentric layers;

periodically feeding sheets of paper into position to cause them to be wrapped about each layer at its completion while the turns of the succeeding layer are coiled thereover;

and concurrently pressing the sheet of paper between rolls during the feeding operation to crease it longitudinally of its marg nal EDWARD F. PARKS. 

